利用图像经过小波变换后系数的分布特点，能够有效地进行图像编码。为了充分利用小波系数的带内相关性和带间相关性，提出了一种有效的位平面编码算法。该算法将各个子带四叉树合并成一棵扫描树，然后再根据扫描树提供的扫描信息进行位平面编码。该算法能够有效地对纹理丰富的图像区域进行编码，比EZW和SPIHT算法具有更好的编码效果。除此之外，该算法还具有实现简单、执行速度快和消耗存储空间资源少等特点，降低了硬件实现的难度，具有很强的实用性。

Image can be encoded effectively by using the spatial distribution characteristic of wavelet coefficients. In order to make full use of the intraband correlation and interband correlation of wavelet coefficients, an effective image coding algorithm is proposed. In the algorithm, subband quadtrees are combined to a scanning tree, and then bitplanes are encoded with the information provided by the scanning tree. The algorithm has better coding performance than EZW and SPIHT for it effectively encodes the image areas which are rich in texture. In addition, the algorithm is also characterized by features of easy realization, fast execution and little memory consumption. So it reduces the difficulty of hardware realization and has good practicability.